JP2003127044A - Direct driven table device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct driven table device that can feed/drive a movable table at a high speed, without increasing the rotational speed of ball-screw shaft close to its limit level or extremely enlarging the pitch for the shaft. SOLUTION: A table-driving mechanism 5 for sliding/driving the movable table 4 comprises a driving motor 51; the ball screw shaft 53, which is driven by the driving motor 51; the first nut 54, which is driven in the axial direction by the shaft 53; the first nut bracket 55, designed to fix the first nut 54 to the movable table 4; the second nut 56, which is driven by the shaft 53 in the direction opposite to the first nut 54; the second nut bracket 57, designed to fix the second nut 56 to a table base 2; and a ball screw shaft support 59, which supports the shaft 53, while the support 59 is arranged to be movable in the axial direction of the shaft 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion table device used in machine tools, semiconductor manufacturing equipment and the like.

[0002]

2. Description of the Related Art In a machine tool, a semiconductor manufacturing apparatus or the like, a linear motion table device as shown in FIG. 5 is conventionally used as a unit for transporting a work or a processing tool to a predetermined position. This linear motion table device has a table base 2, and a movable table 4 provided on the table base 2 via a linear guide 3 is driven by a table drive mechanism 5 including a drive motor 51 and a ball screw 52. The linear guide 3 is slidably driven in the longitudinal direction.

The ball screw 52 includes a ball screw shaft 53 which is rotationally driven by a drive motor 51 and a nut (not shown) which is axially driven and driven by the ball screw shaft 53.
And a nut bracket (not shown) for fixing the nut to the movable table 4, so that when the ball screw shaft 53 is rotated by the drive motor 51, the nut is fed and driven together with the movable table 4 in the axial direction. It has become.

[0004]

In such a linear motion table device, since the table drive mechanism 5 is composed of the drive motor 51 and the ball screw 52, the movable table 4 is accurately fed and driven to a predetermined position. It has the advantage that it can. However, when the number of revolutions of the ball screw shaft 53 approaches the limit number of revolutions, vibration or the like occurs, and when the pitch of the ball screw shafts 53 is extremely increased, the feed accuracy decreases, so that the movable table 4 is fed and driven at high speed. Was difficult.

Further, in the linear motion table device as shown in FIG. 6, the ball screw shaft 53 is supported by the motor 51 and the nut 5.
Since it is taken care of only by No. 4, the rigidity etc. is low and there is a problem that it is not possible to cope with high acceleration / deceleration driving of the movable table 4. The present invention has been made in view of such problems, and an object thereof is to bring the rotation speed of the ball screw shaft close to the limit rotation speed or to increase the pitch of the ball screw shaft extremely. An object of the present invention is to provide a linear motion table device that can drive and drive a movable table at high speed without moving.

[0006]

In order to achieve the above object, the present invention provides a linear motion table comprising a table drive mechanism for slidingly driving a movable table provided on a table base via a linear guide. In the apparatus, the table drive mechanism includes a drive motor, a ball screw shaft that is rotationally driven by the drive motor, a first nut that is axially driven and driven by the ball screw shaft, and the first nut is movable. A first nut bracket for fixing to the table; a second nut driven and driven by the ball screw shaft in a direction opposite to the first nut;
A second nut bracket for fixing the nut to the table base and a ball screw support for supporting the ball screw shaft are provided, and the ball screw support is provided so as to be movable in the axial direction of the ball screw shaft. It is characterized by

With such a construction, the rotation of the drive motor causes the ball screw support to move in the same direction as the moving table by the same stroke, and the moving amount of the moving table is multiplied. The movable table can be driven and driven at a high speed without making the rotation speed close to the limit rotation speed or making the pitch of the ball screw shaft extremely large. Here, as a specific configuration for providing the ball screw support movably in the sliding direction of the movable table, the invention described in claim 2, that is, the ball screw support is provided between the table base and the linear guide. Further, it is possible to employ a configuration in which a linear guide that supports the ball screw support so as to be movable in the axial direction of the ball screw shaft is provided between the ball screw support and the table base.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same or corresponding parts as those shown in FIG. 1 to 4 are views showing an embodiment of the present invention (hereinafter abbreviated as the present embodiment). FIG. 1 is a perspective view of a linear motion table device according to the present embodiment, and FIG. 3 is a sectional view taken along line III-III of FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV of FIG.

In FIG. 1, reference numeral 1 is a linear motion table device according to the present embodiment, and the linear motion table device 1 comprises a table base 2, a linear guide 3, a movable table 4 and a table drive mechanism 5. ing. The movable table 4 is provided on the table base 2 via a linear guide 3, and a table drive mechanism 5 for slidingly driving the movable table 4 in the longitudinal direction of the linear guide 3.
2 and 3, a drive motor 51 and a ball screw shaft 5 in which a right screw and a left screw having the same pitch are formed on one screw shaft that is rotationally driven by the drive motor 51.
3, a first nut 54 axially driven and driven by the ball screw shaft 53, and a first nut bracket 55 for fixing the first nut 54 to the movable table 4. The table drive mechanism 5 further includes a second nut 56 that is driven by the ball screw shaft 53 in the same stroke in the opposite direction to the first nut 54, and the second nut 56 is driven by the second nut bracket 57. It is fixed at 2.

As shown in FIG. 4, the table drive mechanism 5 also includes a ball screw support 59 that supports both ends and the center of the ball screw shaft 53 via bearings 58. This ball screw support 59 is a table base 2
Is provided between the table base 2 and the ball screw support 59, and a linear guide 60 that supports the ball screw support 59 movably in the axial direction of the ball screw shaft 53 is provided between the table base 2 and the ball screw support 59. Has been. In addition,
The drive motor 51 is attached to the ball screw support 59 via a motor bracket 61.

In such a structure, the drive motor 51
When the ball screw shaft 53 is driven to rotate clockwise, for example, the first nut 54 is driven to the right in FIG.
As a result, the movable table 4 moves to the right in FIG. At this time, the driving force to the left in FIG. 2 acts on the second nut 56, but the second nut 56 does not move to the second nut bracket 57.
Since it is fixed to the table base 2 by
Instead of the nut 56, the ball screw support 59 moves to the right in FIG. As a result, the movable table 4 moves with a stroke twice as large as that of the conventional table, so that the rotation speed of the ball screw shaft 53 approaches the limit rotation speed or the pitch of the ball screw shaft 53 is extremely increased. It is possible to feed and drive the movable table 4 at high speed without any need.

Further, in this embodiment, the ball screw shaft 53
Since both ends and the center of the ball screw are supported by the ball screw support 59 via bearings 58, respectively,
Both the double anchor support method and the single anchor support method can be adopted as the support method of No. 3, and pretension can be applied as a measure against thermal displacement. In addition,
The present invention is not limited to the above embodiment,
Various modifications can be implemented without departing from the gist of the present invention. For example, an example in which the ball screw shaft 53 is formed with left and right screws having the same pitch is shown, but different pitches may be used.

[0013]

As described above, according to the linear motion table device of the present invention, the rotation of the drive motor causes the ball screw support to move in the same direction as the movable table by the same stroke, and the movable table is moved. Since the amount of movement is increased, the movable table can be driven and driven at high speed without making the rotation speed of the ball screw shaft close to the limit rotation speed or making the pitch of the ball screw shaft extremely large.

[Brief description of drawings]

FIG. 1 is a perspective view of a linear motion table device according to an embodiment of the present invention.

FIG. 2 is a sectional view of the linear motion table device shown in FIG.

3 is a sectional view taken along the line III-III of FIG.

4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a perspective view of a conventional linear motion table device.

FIG. 6 is a diagram showing another conventional linear motion table device.

[Explanation of symbols]

2 table base 3 linear guide 4 movable table 5 Table drive mechanism 51 drive motor 53 ball screw shaft 54 First Nut 55 First Nut Bracket 56 Second nut 57 Second nut bracket 59 Ball screw support 60 linear guide

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G12B 5/00 G12B 5/00 T

Claims (2)

[Claims] 1. A linear motion table device comprising a table drive mechanism for slidingly driving a movable table provided on a table base via a linear guide, wherein the table drive mechanism includes a drive motor and a drive motor. A ball screw shaft that is rotationally driven, a first nut that is axially driven and driven by the ball screw shaft, a first nut bracket for fixing the first nut to the movable table, and a ball screw shaft. It is composed of a second nut that is driven and driven in a direction opposite to the first nut, a second nut bracket for fixing the second nut to the table base, and a ball screw support that supports the ball screw shaft. At the same time, the ball screw support is provided so as to be movable in the axial direction of the ball screw shaft. Table device. 2. The ball screw support is provided between the table base and the linear guide, and the ball screw support is movable in the sliding direction of the movable table between the ball screw support and the table base. The linear motion table device according to claim 1, wherein a linear guide that supports the linear motion table is provided.